Grid or element for secondary batteries.



PATENTED SEPT. 19, 1905.

W. GARDINER. GRID 0R ELEMENT FOR SECONDARY BATTERIES.

APPLIGKTION'I'ILED AUG. 22, 1904.

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UNITED STATES PATENT onrroa.

WILLIAM GARDINER, OF CHICAGO, ILLINOIS, ASSIGNOIL BY MESNEAS- SIGNMENTS,TO UNIVERSAL ELECTRIC STORAGE BATTERY COMPANY,

A CORPORATION OF DELAWARE.

GRID OR ELEMENT FOR- SECONDARY BATTERIES.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed August 22, 1904. Serial No. 221,644.

To (ZZZ whom it may concern.-

tion of the same, reference being had to the fall to the bottom of thecell.

accompanying drawings, and to the letters of reference therein, whichform a part of this specification. I

This invention relates to improvements in elements for secondarybatteries and of the class known as lead-plate batteries. Heretofore aserious difficulty has existed in the use of pasted and other plates,owing to the fact that in charging and discharging the battery a greateror less degree of disintegration of the active material takes place,causing the same to be separated from the plate and to This in manyinstances accumulates in suflicient quantities to short-circuit the celland seriously detracts from the efliciency of the cell.

The object of myinvention is to provide an element or battery-plate soconstructed as to retain the active material permanently in the plate,thus preventing the same falling therefrom. The construction of theplate also precludes the possibility of the active material being washedtherefrom by the electrolyte by the jolting or jarring of the cells.

It is also an object ofmy invention to increase thesurface of metaladapted to be exposed to electrolytic action to a maximum by the use ofa minimum weight of the metal.

The invention consists in the matters hereinafter contained, and morefully pointed out and defined in the appended claims.

In the drawings, Figure 1 is a perspective view of a plate embodying-myinvention,showing the same broken away at the bottom. Fig. 2 is asimilar perspective View showing the sheet forming the plate extendedlongitudinally of the plate or partly unfolded to show the construction.

As shown in said drawings, said plate A comprises a sheet of metal, suchas relatively pure lead or other metal, which is rolled into very thinsheets and closely perforated, said perforations extendingtherethroughand, if

preferred, being formed in the plate at the time the plate is rolled.When said plate has been reduced to a desired thickness and theperforations made therein by rolling or otherwise, the same is foldedtransversely, as shown in the drawings, into a plurality of folds, whichmay be of any desired width and the outer edges of which are forcedclose together, leaving the central portion of the fold curvedoutwardly, as shown in Fig. 1. A lug C is then burned on the top thereofnear one side I of the same, and the adjacent folds of the sheet on eachside thereof are burned together at a plurality of points, as shown inFig. 1. Said lines "of lead-burning are indicated, respectively, by a a.The plate is now ready to be formed and is preferably formed electrochemically by processes forming the subject-matter of other inventions or inany desired manner, but which as afinal result reduces the surface ofthe sheet on both sides thereof and in the folds to a metallic oxid. Inthe process of converting a portion of the metal into an oxid thevolume'is greatly increased, thus greatly compressing the metallic oxidwithin the folds ofthe plate. The greater part of the oxid formed on theouter surfaces of the plate or grid is then scraped away to prevent thedisintegration from the plate forming a short circuit, and the elementis then ready for use.

The operation is as follows: The electrolyte finds ready access throughsaid apertures and permeates every part of the element within the foldsof which said oxid is secured. It is obvious that as a result theavailable surface for electrolytic. action is enormously increased onboth sides of the sheet and that the charging and discharging. of thecell can have no eifect Whatever to cause buckling or the disintegrationof the oxid from the element. It is also obvious that an elementconstructed as described may be made of comparatively little weight andthat owing to the thinness of the same and the great surface exposed toelectrolytic action the rate of charging or discharging may be much morerapid than ordinary withoutpossibility of injury. Obviously, also, thethickness of said grid as a whole may be varied as desired by varying ofthe width of the folds, thus adapting the plate for use in any desiredsize or type of cell. While in the specification the element has beendescribed as first folded or shaped and then formed, I do not desire tobe limited to a grid so treated, as, obviously, a metallic sheet may beformed and the oxid converted into a metallic sponge previous tofolding, if preferred.

Obviously details of construction may be varied Without departing fromthe principles of my invention.

I claim as my invention 1. An electrode for accumulators comprising athin sheet of relatively pure lead provided With a plurality ofclosely-arranged apertures extending therethrough, said sheet beingfolded transversely thereof into a plurality of folds the Walls of Whichare curved oppositely forming single pockets and the adjacent edgesthereof being forced into close contact and integrallyconnected at aplurality of points intermediate the lateral edges of the sheet.

2. An electrode for accumulators comprising a thin sheet of relativelypure lead, provided with a plurality of closely-arranged aperturestherethrough, said sheet being folded transversely into a plurality offolds, the central portions of adjacent folds being out of contact andthe outer margins thereof forced l close together and integrallyconnected at a plurality of vertical lines on opposite faces.

3. A sheet of thin pure sheet metal provided with a plurality ofclosely-arranged apertures extending therethrough, said sheet beingfolded transversely providing a plurality of folds having their marginsforced into close contact and integrallyconnected together at aplurallVlLLIAM (1 ARDI NEH.

\Vitnesses:

I-IJALMAR S. RUDD, W. W. \VITHENBURY.

